I just hooked up my first uniflow system on a plane yesterday. Before yesterday the plane ran HORRIBLE when upsidedown even though the tank was almost right were it should have been heigth wise,and there was noticable leaning toward the end of tank. The only other issue was I was using a rather large 14oz tank that might have been trying to push too much fuel into the engine depending on the planes attitude,such as upside down even though the tank was only maybe 1/4" above the needle while inverted(1/4" below normally). Well,I stuck in a 10oz tank which was able to let me raise the tank about 1/4",and I installed the uniflow setup. Now the engine is running GREAT. Almost no noticable difference while upsidedown or anywhere else. It also seems to run good on almost an empty tank,but I havent actually ran it that low in the air yet. Anyways.....I'm not sure if it was the smaller tank,the raising the tank 1/4",or the uniflow..........but I can say the uniflow doesnt hurt! And seems to work great. I will say the bubbles in the tank concerned me,but you always get foaming regardless,and thus far it doesnt seem to affect anything. So,I will defenitly be installing more uniflow systems in the future and its definetly worth trying!

By the way,I did this with an upright mounted .91 thunder tiger 4-stroke.